I agree that the most reliable way to solve your problem is to buy from a dealer. If you are not satisfied with his offer (strange), then you can visit the auto parts stores in your city, I'm sure there are several even near your house. There is another option - these are used locks, but I do not advise you to buy them, since there is no guarantee of how long they will serve you. I once bought a used lock for the front door and after about a month its core fell into disrepair and had to be replaced. Yes, I took a little time to find out the
differences between door locks, but it was worth it. In the end, I want to tell you that it is best to buy only new locks, and I have already told you where to do it.